I was almost asleep last night when I suddenly heard someone _____ at thedoor.(2013年真题）
A: be knocking
B: knocking
C: to knock
D: having knocked
A: be knocking
B: knocking
C: to knock
D: having knocked
举一反三
- I was almost asleep last night.........................(as, when) I suddenly heard someone knocking on the door.
- I was almost asleep last night when I suddenly heard someone ( ) at the door.
- Suddenly he heard someone（）gently on the window. A: knock B: knocking C: knocked D: to knock
- I heard someone _______ loudly at the door while I was listening to the radio. A: knock B: knocking C: to knock D: knocked
- 智慧职教: I was almost asleep last night when I suddenly heard the dog ________ outside.